CN111479967A

CN111479967A - Rear-loading bucket loader

Info

Publication number: CN111479967A
Application number: CN201880080882.3A
Authority: CN
Inventors: 理查德·斯蒂拉德·格尼
Original assignee: Gert Private Ltd
Current assignee: Gert Private Ltd
Priority date: 2017-12-15
Filing date: 2018-12-12
Publication date: 2020-07-31
Also published as: JP2021507142A; EP3697970A1; CA3082968A1; US20210071384A1; AU2018383128A1; RU2747194C1; AU2018383128B2; MX2020006156A; WO2019116247A1; BR112020010961A2

Abstract

The present invention provides a rear dump bucket loading mechanism for transporting material along an overhead trajectory from a fill position to a discharge position. The rear dump bucket loading and unloading mechanism comprises: at least one control arm (18) pivotally connected at one end to the chassis frame and pivotally connected at the other end to a thrust end of a loading arm (20); and a bucket (16) pivotally connected to the loading end of the load arm. Rotation of the control arm about its pivotal connection moves the thrust end of the load arm from a terminal high point when the loading end of the load arm is positioned towards the bottom of its trajectory for bucket filling and from a terminal low point when the loading end of the load arm is positioned towards the height of its trajectory, which lowers the center of gravity of the loading mechanism while maintaining sufficient bucket height to clear the cab of the vehicle.

Description

Rear-loading bucket loader

Technical Field

The invention relates to a rear-dump bucket loader.

Background

Rear dump bucket loaders, also known as overhead loaders, on either a boom loader or a tumble loader were introduced to the market about 60 years ago and are used to move or load material such as soil or gravel from a location in front of the loader to a receiver located at a location behind the loader.

Loaders typically include a bucket or bucket at the end that is fitted to the boom of the machine. The material to be transferred is loaded into a bucket or dipper located in front of one of the axles of the machine. The boom and then bucket are raised along a track, up over the machine and down to the other side, which allows the material to be discharged into a receiver positioned in front of the second axle of the machine or onto the ground.

The energy required for boom movement is typically achieved by a hydraulic/electric actuator or winch and cable.

While rear dump bucket loaders have many significant benefits, they have a number of serious drawbacks, particularly mechanical disadvantages due to the bucket being located at the end of the long boom (which results in poor leverage, requiring an unfavourable deep gear set to generate the high torque and low speed required for digging up, but when applied to tasks when only lifting the bucket (requiring a lighter application of force but a higher speed), high torque and low speed are not appropriate). Further, the bucket on the long boom end adversely affects the stability of the machine.

Another difficulty faced by earlier machines was the visibility difficulty, where the operator had a clear view of one operation but did not know the other, a situation that is now easily overcome with modern industrial-grade cameras. Other challenges faced include preventing spillage from the bucket, where the angle of the bucket relative to the horizontal changes gradually during transport.

It is an object of the present invention to provide a rear dump bucket loading mechanism that at least partially alleviates some of the above problems.

Disclosure of Invention

According to the present invention there is provided a rear dump bucket loading mechanism or tilt-up loading mechanism (OVERSHOT L OADER) for transporting material along an elevated trajectory from a filling position at a loading end of a vehicle to a discharge position at a discharge end of the vehicle, the rear dump bucket loading mechanism comprising;

a chassis frame for supporting a body of a vehicle;

at least one control arm for controlling the movement of at least one loading arm, one end of the control arm being pivotally connected to the chassis frame and the other end of the control arm being pivotally connected to the first/thrust end of the loading arm;

and a bucket pivotally connected to the loading end of the load arm,

wherein rotation and/or counter-rotation of the control arm about its pivotal connection to the frame causes the thrust end of the load arm to move from a terminal high point when the loading ends of the bucket and load arm are positioned towards the bottom of their trajectory for bucket filling and/or discharging, and from a terminal low point when the bucket end of the load arm is positioned towards the height of its trajectory, thereby lowering the center of gravity of the loading mechanism while keeping the bucket height high enough to clear the cab located on the vehicle.

Also provided is: the rear dump bucket handling mechanism comprises at least one cam track extending at least partway along the length of the chassis frame and the load arm further comprises a roller fixed at a point along its length, the load arm roller being receivable in use on the cam track for guiding and supporting movement of the load arm from the fill position to the discharge position.

In a preferred embodiment of the invention, the rear dump bucket loading mechanism includes a cross shaft pivotally mounted across the width of the chassis frame and a control arm mounted at either end of the cross shaft. Each control arm is pivotally connected to the loading arm.

The backhoe loader also includes two cam tracks that can be positioned on opposite sides of the chassis frame and separated by a distance large enough to accommodate a centrally mounted cab.

Also provided is: each cam track on either side of the chassis frame includes: a loading cam track portion extending from the filling end of the chassis frame toward a middle of the chassis frame; and a discharge cam track portion extending from about a middle portion of the chassis frame toward a discharge end of the chassis frame.

The discharge cam track section may be pivotally connected to the loading cam track section.

The loading cam track section and the discharge cam track section are profiled to support the loading arm while transporting the bucket through the appropriate trajectory.

The loading cam track section is generally convex in profile and the discharge cam track section is generally concave in profile.

The load cam track portion may also include a latch at its lowermost end for engaging the roller when in the fill position, thereby allowing downward pressure on the bucket during filling.

Alternatively, in a more aesthetic embodiment of the invention, the cam plate may be fixed to the load arm and the roller may be fixed to a bracket rigidly mounted to the chassis frame, the roller engaging the cam plate to allow a downward force to be applied to the bucket during filling.

Also provided is: the discharge cam track section is pivotable to allow the load arm to lower the bucket closer to the ground to a deployed position.

The chassis frame comprises wheel axles and wheels when on a wheel loader or an endless track when fitted to a tracked vehicle.

The bucket is connected to the load arm by a system of pins and linkages and is articulated under load by a power source.

The movement of the control arm may be driven by a hydraulic cylinder, electrical actuation, or other suitable energy source.

Also provided is: a single stroke of the power source moves the thrust end of the load arm from its terminal high point to its terminal low point to drive only the bucket from its fill position to the top of its trajectory, and a single reverse stroke of the power source moves the thrust end of the load arm from its terminal low point back to its high point to move the bucket from the top of its trajectory to its discharge or deployed position, whereby the forward and reverse strokes of the power source are effected by electronically controlled hydraulics or the like.

The rotation and counter-rotation of the cross shaft and thus the control arm may be electronically triggered, as may the position of the bucket relative to the loading arm during its trajectory from filling to discharging, to prevent spillage. Alternatively, other suitable means may be employed.

The geometry of the cam track, the location of the rollers on the load arm, and the effective mounting point of the thrust end of the load arm at its terminal low point provide a reduced overhead trajectory and lowered center of gravity of the bucket while transferring loads from the vehicle load side to the vehicle discharge side, while also enabling the bucket to extend in front of and behind the vehicle to accommodate sufficient load and unload clearance when the thrust end of the load arm is at its terminal high point.

Drawings

Preferred embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

FIG. 1 is a schematic view of an overhead loader of the present invention;

FIG. 2 is a side view of an embodiment of the present invention during bucket filling;

FIG. 3 is a side view of an embodiment of the present invention illustrating an early position as the bucket is powered toward its apex from its stowed position;

FIG. 4 is a side view of an embodiment of the present invention illustrating the load arm and bucket at the apex of the trajectory;

FIG. 5 is a side view of an embodiment of the present invention illustrating the start of the discharge sequence;

FIG. 6 is a side view of an embodiment of the present invention illustrating a discharge point;

FIG. 7 is a side view of an embodiment of the present invention illustrating the bucket near ground level on the discharge side;

FIG. 8 is a plan view of an embodiment of the present invention;

FIG. 9 is a diagram detailing the use of the cams, rollers, load arms, and control arms as the bucket is powered progressively from filling to discharging;

fig. 10 illustrates an alternative embodiment of the present invention.

Detailed Description

Referring to fig. 1 to 10, like features of the present invention are indicated by like reference numerals.

Referring to fig. 1-8, a rear dump bucket loader mechanism (10) for transporting material in an overhead trajectory from a bucket fill position (fig. 2) at one end of a vehicle to a dump position (fig. 6 and 7) at the other end of the vehicle includes a chassis frame (12) mounted on axles and wheels (14) for supporting the mechanism. The cross shaft (29) is pivotally mounted across the width of the chassis frame (12). See (fig. 8). One end of a pair of control arms (18) are each fixed to the opposite end of a transverse shaft (29). The other end of each control arm (18) is pivotally connected to the thrust end of the loading arm (20) at a pivot point (25).

The free end of the load arm 20 is rigidly connected by a member (40) and pivotally connected to the bucket (16) at a pivot point (27) by a pin, linkage and power source (details not shown). In this way, the bucket (16) is indirectly connected to the center of mass of the machine (10), which allows the degree of springiness to be designed in the present invention.

A pair of cam tracks (35) on opposite sides of the machine support rollers (32) attached at fixed points along the length of each loading arm (20), and the rollers (32) are receivable on the cam tracks (35) during operation.

Each cam track (35) comprises: a loading cam track portion (34) fixed to the chassis frame (12) at a loading end and extending part way along the length of the chassis frame; and a discharge cam track section (36) pivotally connected to the loading cam track section (34) at a pivot point (44) and extending toward the discharge end of the chassis frame (12).

Referring to fig. 2-7, the loading cam track portion (34) has a generally convex profile, while the discharge cam track portion (36) describes a generally concave profile. However, it should be understood that other profiles may achieve similar results.

Referring to fig. 1-7, and in one embodiment of the invention, the loading cam track portion (34) further includes a latch (42) at its loading end for engaging the roller (32) when the loading arm (20) is in the fill position, thereby retaining the roller on the cam track portion (34), which allows the operator to exert a downward force on the bucket (16) during filling without the roller lifting off the loading cam track portion (34).

Alternatively, and with reference to fig. 10, in a more aesthetic embodiment of the invention, the cam plate (51) is fixed to the loading arm (20) and the roller (52) is fixed to a bracket (50) rigidly mounted to the chassis frame (12). These elements allow a downward force to be applied to the bucket during filling.

The discharge cam track section (36) is connected to the loading cam track section (34) at a pivot point (44), which pivot point (44) allows the operator to set the discharge end height of the discharge cam track section (36) so as to allow a consistent dump height or even lower the bucket (16) to ground level as shown in fig. 7 to allow material to be spread while moving.

In use, and with reference to fig. 2, when in the filling position, the pivot point (25) joining the control arm (18) to the load arm (20) is at its highest termination point, which ensures that the load arm (20) maintains a clearance above the load-end axle, and the pivot point is in such a position that: a latch (42) prevents the roller (32) from being lifted off the cam track portion (34) when a downward force is applied to the dipper (16).

The maximum power is absorbed when the bucket is filled (fig. 2). Thereafter, the energy demand is reduced, since energy is dedicated only to lifting the bucket (16). The profile of the lift cam (34) is designed to direct this excess energy to accelerate the mass of the bucket (16) over its travel to its high point (fig. 4).

Referring to fig. 3, once the bucket has been filled, pivot point (25) is rotated under power about pivot point (29) from its terminal high point (fig. 2) towards its terminal low point illustrated in fig. 4.

As the load arm (20) is connected to the control arm (18) at pivot point (25), any incremental decrease in the height of the pivot point (25) powers the roller (32) up the incline of the load cam track portion (34), which displaces the load arm (20) and bucket (16) from their load position (as depicted in fig. 2) through the position depicted in fig. 3 until they are progressively displaced to a substantially vertical position as illustrated in fig. 4, because the pivot point (25) is driven by the force towards its lowest end point (fig. 4) as the bucket (16) is progressively displaced towards its apex.

It will be appreciated that the geometry of the cam track and all linkages are designed to lower the height of the overhead trajectory of the bucket (16), correspondingly lowering the center of gravity of the loaded bucket, while still allowing sufficient clearance between the top of the cab and the bucket assembly.

One stroke of the power source (not shown) will only move the pivot point (25) from its high point as depicted in fig. 2 until its terminal low point as depicted in fig. 4, whereby it can be seen that only the load arm (20) and bucket (16) will be driven from their filling position until displaced to a more or less vertical position. Then, a reverse stroke of the power source is required to displace the load arm from this position illustrated in fig. 4 through the intermediate position illustrated in fig. 5 until the load arm and the bucket reach the discharge position illustrated in fig. 6 and even their deployed position as illustrated in fig. 7.

By definition, the pivot point (25) must come to a complete stop when it reaches its lowest end point before it can begin its return stroke. It will be appreciated that as the loaded bucket and load arm accelerate to their positions as depicted in fig. 4, the loaded bucket and load arm will accumulate a significant amount of momentum. This momentum allows the bucket to easily cross the valley at point (44).

Referring to fig. 9, at points 7a and 7b, the time delay for reverse flow of fluid to the hydraulic cylinder or the like will be designed to be equal to the time it takes for the load arm to cross the valley between the load cam (34) and the discharge cam (36).

The rotation and counter-rotation of the control arm (18) about its pivot point (29) is initiated by a power source that is electronically triggered or the like, as is the position of the bucket (16) relative to the loading arm during its trajectory from filling to discharging, to prevent spillage in use.

Although the figures illustrate wheeled vehicles, the loader may also be used on tracked vehicles.

It will be appreciated that one of the fixed parameters associated with conventional rear dump bucket loaders is that the length of the load arm or boom carrying the bucket must not be shorter than half the length of the vehicle plus the sum of the bucket fill gap required before the fill end of the vehicle and the bucket discharge gap required before the discharge end of the vehicle (which is required to fill the receiver).

For example, if the total length of the vehicle plus the clearance is 5.6m, the loading arm cannot be shorter than 2.8 m. Furthermore, in the case of wheel mounted rear dump bucket loaders, the thrust end of the loading arm needs to be fixed to the vehicle at a minimum height so that the loading arm does not interfere with one axle during bucket filling or with the other during spreading of the material. For example, if the load arm is 2.8m long, the thrust end of the load arm needs to be at least 2.2m above the ground to clear the wheel axle, as illustrated, the bucket will be 5m (2.2m +2.8m) from the ground at the height of its trajectory. An additional 0.4m is added to the center of gravity of the loaded bucket, and when in fact the bucket needs only 3.4m above the ground to pass over the top of the cab, the total center of gravity of the loaded bucket is at an unnecessary height of 5.4m, as described in this example.

In order to lower the centre of gravity as much as possible but still over the cab, the thrust pin connecting the load arm to the bucket therefore only needs to be 3.4m to pass over the cab, a load arm length of less than 2.8m means that the joint at point (25) will be 0.6m above the ground.

In the above invention, this is achieved by having the pair of control arms (18) mounted on the ends of the cross shaft (29) separated by a gap wide enough to accommodate a centrally mounted cab. The free ends of these control arms (18) can reciprocate between a terminal high point and a terminal low point (i.e. 2.2m above the ground as the minimum height to clear the front wheel axle during bucket filling in this example and 0.6m above the ground as the calculated height to allow the bucket to clear the cab, all heights having the lowest center of gravity).

The free end of the control arm (18) becomes the ideal anchor point (25) for the loading arm (20) during bucket filling at its initial high point. In order to maximize vehicle stability, it is desirable to keep the bucket as low as possible during the trajectory of the loaded bucket. This is achieved by rotating the control arm (18), and thus the load arm (20) and bucket (16), to the lowest possible point that still leaves sufficient clearance between the cab and the bucket.

Furthermore, the loading cam track portion (34) supporting the loading arm by means of rollers is shaped to displace the bucket in a trajectory from its loading position to its high point, which allows cab clearance, and similarly the discharge cam track portion (36) is shaped to transport the bucket in a trajectory from its high point to its discharge position or even ground level.

The present invention therefore meets the need to provide a rear-dump bucket loader in which the bucket follows a suitable trajectory from the high point of filling to the bucket and then from the high point of the bucket to the discharge point of the bucket, and which is additionally capable of spreading material at ground level (if so desired).

The present invention provides a system whereby, in one full power stroke of the actuator as illustrated in fig. 4, the thrust end of the load arm (25) is powered from a terminal high point for bucket loading as depicted in fig. 2 to a terminal low point to displace the bucket to its highest point. The reverse stroke of the power drive will displace the bucket from its high point to its discharge position as illustrated in fig. 6 or even to ground level as illustrated in fig. 7.

With reference to fig. 9, the use of a cam of specific profile ensures that the loading arm (20) is always supported by two elements associated with each other, which enables the bucket to follow the desired trajectory. The first element is a load arm anchor point (25) which is progressively displaced from its uppermost termination point to its lowermost termination point. The second element is a support provided to the loading arm. This is achieved by engaging the roller (32) at a point along the length of the loading arm (20) which will push against a given point on the loading cam track portion (34) for bucket filling. As the thrust point (25) of the load arm (20) moves gradually downwards, the roller will be supported at higher and higher points on the load cam (34) in order to lift the bucket to the next position on its trajectory. With this successive increment, the roller (32) also needs support at each increment point in order to scribe the desired trajectory. By combining these support points into a smooth curve, it becomes the profile of the loading cam (34) which, together with the moving anchor point (25), displaces the loading arm (20) from filling in such a way as to give the bucket the required trajectory until it reaches its highest point.

In order to displace the bucket (16) from its uppermost position to its dumping position or even down to ground level, a powered drive is required to begin reversing the direction of the anchor point (25) from its lowermost terminal point towards its upper point. As this occurs incrementally to displace the bucket toward its dump position, the load arm rollers need to be supported at each incremental point. The profile of the discharge cam (36) is indicated by combining these support points into a smooth curve.

The present invention thus provides a rear dump bucket loader that is therefore more efficient and cost effective than conventional loaders.

Claims

1. A rear dump bucket loading mechanism for transporting material along an overhead trajectory from a filling position at a loading end of a vehicle to a discharge position at a discharge end of the vehicle, the rear dump bucket loading mechanism comprising;

a chassis frame for supporting a body of a vehicle;

at least one control arm for controlling the movement of the at least one loading arm, one end of the control arm being pivotally connected to the chassis frame and the other end of the control arm being pivotally connected to the first/thrust end of the loading arm;

and a bucket pivotally connected to the loading end of the load arm,

wherein rotation and/or counter-rotation of the control arm about its pivotal connection to the frame causes the thrust end of the load arm to move from a terminal high point when the loading ends of the bucket and load arm are positioned towards the bottom of their trajectories for bucket filling and/or discharging, and from a terminal low point when the loading ends of the bucket and load arm are positioned towards the height of their trajectories, thereby lowering the center of gravity of the loading mechanism while keeping the bucket height high enough to clear the cab located on the vehicle.

2. A rear dump bucket loading mechanism as defined in claim 1 wherein the mechanism further includes at least one cam track extending at least partway along the length of the chassis frame and shaped to support the load arm when the bucket is transported through the appropriate trajectory.

3. A rear dump bucket loader as claimed in claim 2 wherein the loading arm further comprises a roller fixed at a point along its length, the loading arm roller being receivable in use on the cam track for guiding and supporting movement of the loading arm from the filling position to the discharge position.

4. A rear dump bucket loading mechanism as set forth in claim 1 wherein the mechanism includes a cross shaft pivotally mounted across the width of the chassis frame and control arms mounted at either end of the cross shaft, and wherein each control arm is pivotally connected to the load arm.

5. The rear dump bucket loader of claim 4, wherein the mechanism further comprises two cam tracks, the two cam tracks being positionable on opposite sides of the chassis frame.

6. The rear dump bucket loader of claim 5, wherein each cam track further comprises two portions: a loading cam track portion extending from a loading end of the chassis frame toward a middle of the chassis frame; and a discharge cam track section pivotally connected to the loading cam track section and extending from approximately a middle of the chassis frame toward a discharge end of the chassis frame.

7. The rear dump bucket loader of claim 6, wherein the loading cam track portion is generally convex in profile and the discharge cam track portion is generally concave in profile.

8. A rear dump bucket loader as defined in any one of claims 6 or 7 wherein the discharge cam track section is pivotable to allow the load arm to lower the bucket closer to the ground to a deployed position.

9. A rear dump bucket loader as claimed in any one of claims 6 to 8 wherein the loading cam track section includes a latch at its lowermost end for engaging the roller in the filling position to allow downward pressure on the bucket during filling.

10. A rear dump bucket loader as claimed in any one of claims 6 to 8 wherein the cam plate is secured to the load arm and the rollers configured to engage the cam plate are secured to a bracket rigidly mounted to the chassis frame to allow a downward force to be applied to the bucket during filling.

11. A rear bucket loader as claimed in any one of claims 6 to 10 in which the geometry of the cam track, the location of the rollers on the loading arm and the effective mounting point of the thrust end of the loading arm at its terminal low point provide a reduced overhead trajectory and lowered centre of gravity of the bucket when transferring a load from the loading end of the vehicle to the discharge end of the vehicle and ensure extension of the bucket at the loading end for bucket filling and extension at the discharge end to provide space for discharge into the receiver or lowering the bucket close to the ground.

12. A rear dump bucket loader as defined in any one of claims 1 to 11 wherein the rotation and counter-rotation of the control arm is driven by hydraulic cylinders, electric actuation or other suitable power source.

13. A rear-dump bucket loader as defined in claim 12 wherein the single stroke of the power source is all that is required to gradually drive the thrust end of the load arm from its terminal high point to its terminal low point to thereby power the bucket from its fill position gradually to the top of its trajectory, and the single reverse stroke of the power source is all that is required to gradually drive the thrust end of the load arm back from its terminal low point toward its high point to thereby power the bucket from its high position gradually toward its discharge or deployed position at the discharge end of the vehicle.

14. A rear dump bucket loader as defined in claim 13 wherein the single stroke of the power source is all that is required to drive the thrust end of the load arm gradually from the high point to its terminal low point to power the bucket to gradually return from its discharge or deployed position to the top of its trajectory, and the single reverse stroke of the power source is all that is required to drive the thrust end of the load arm gradually back to its terminal high point to power the bucket from its high point to its below ground fill position at the fill end of the vehicle.

15. A rear dump bucket loader as defined in claims 12 and 13 wherein a complete cycle from bucket filling to discharging and back to its filling position requires one single stroke of the power source followed by a reverse stroke and then again a single stroke of the power source followed by a reverse stroke.

16. A rear loader as claimed in any one of claims 13 to 15 wherein the activation of the power source is achieved using electronically controlled hydraulic means or other suitable means.

17. A rear bucket loader as claimed in any one of claims 1 to 16 wherein the bucket is connected to the loading arm by a system of pins and linkages and is articulated under load by a power source.

18. A rear dump bucket loader as claimed in any one of claims 1 to 17 wherein the position of the bucket relative to the loading arm during its trajectory from filling to discharging is continuously variable to prevent spillage of the contents during the bucket stroke from filling to discharging.

19. A rear bucket loader as claimed in any one of claims 1 to 18 wherein the chassis frame includes axles and wheels when on the wheel loader or an endless track when fitted to the tracked vehicle.